As shown in the figure, a circular shear is put together into an approximate rectangle. Given that the perimeter of the rectangle is 33.12 cm, what is the area of the shadow in square centimeter? It's better to make the details clear,

As shown in the figure, a circular shear is put together into an approximate rectangle. Given that the perimeter of the rectangle is 33.12 cm, what is the area of the shadow in square centimeter? It's better to make the details clear,

So: radius = 33.12 × (2 × 3.14 + 2) = 4cm, I don't know which part of the shadow area is, please ask in time!